Here anions and cation of two reagents interchange between themselves.
2 molecules of HCl (hydrochloric acid) reacts with 1 molecule of (sodium sulphite) to produce 2 molecules of NaCl (sodium chloride) and 1 molecule of (sulphurous acid)
The chemistry of a soap molecule is such that one end of it has a polar covalent bond, while the tail is make up of carbon and hydrogen atoms that have non-polar bonds.